Tiarella plant named `Mint Chocolate`

ABSTRACT

A new and distinct hybrid Tiarella plant characterized by deeply lobed, highly colored foliage and tawny-pink flowers in profusion.

The present invention relates to a new and distinct hybrid of Tiarella,which originated as a cross-pollination of Tiarella `Pinwheel`(unpatented, seed parent) and an unnamed, unpatented deeply lobedTiarella seedling (pollen parent). Tiarella is in the Saxifrage family(Saxifragaceae). The new Tiarella is a result of controlledhybridization at Terra Nova Nurseries, Inc., in Canby, Oreg. This hybridwas selected from a large selection of seedlings. Seed and pollen parentplants were retained to observe habit and to compare with the newvariety. The new variety has been reproduced only by asexual propagation(division and tissue culture). Each of the progeny exhibits identicalcharacteristics to the original plant and is unlike any Tiarella offeredby any American nursery or book known to me as evidenced by thefollowing characteristics:

1. Unique form and foliage shape; and

2. Tawny-pink flowers in profusion.

Asexual propagation by division and tissue-culture as done in Canby,Oreg., shows that the foregoing characteristics and distinctions cometrue to form and are established and transmitted through succeedingpropagations.

BRIEF DESCRIPTION OF THE DRAWING

The drawing is Tiarella `Mint Chocolate` at the end of its bloomingcycle in May.

DETAILED PLANT DESCRIPTION

The following is a detailed description of the new Tiarella hybrid basedon observations of specimens in Canby, Oreg. The color descriptions areall based on The Royal Horticultural Society Colour Chart and TheAmerican Rhododendron Society publication: "A Contribution TowardStandardization of Color Names in Horticulture."

Foliage:

Type.--Evergreen in USDA hardiness Zones 5 and above. Herbaceous in USDAhardiness zones 3 and 4.

Shape.--Palmate, deeply 7-lobed, irregularly toothed; central lobeelongated, tapers to a fine point from a narrow base; lobe tip finelyincised.

Length.--10-14 cm.

Width.--8-12 cm.

Petiole length.--Varies 10-20 cm.

Margins.--Crenate with a hard short point (mucronate).

Apex.--Rostratus (terminating gradually in a long point).

Base.--Cordate.

Texture.--Slightly rugose, light sheen.

Leaf arrangement.--Basal clump.

Venation.--Reticulate.

Flower:

Petal count.--5 petals. 5 calyx lobes.

Petal shape.--Triangular, clawed.

Flower type.--Complete, calyx tube campanulate, ovary superior.

Flower size.--0.80 cm.

Flower number.--40-45 blooms per raceme.

Peduncle girth.--1.5 mm.

Peduncle texture.--Puberulent.

Blooming habit.--Simple upright raceme to 25 cm. 30-35 racemes persecond year plant. No tendency towards fasciation observed.

Bloom period.--Early April to Mid-May. Minor sporadic rebloom in summerand fall.

Fragrance.--Lightly fragrant.

Fruit:

Type.--Dehiscent capsule of 2 unequal parts.

Fertility.--Fertile.

Size:

Height.--19 cm (2-year-old plant grown in Canby, Oreg.).

Width.--30 cm (2-year-old plant grown in Canby, Oreg.).

Color Characteristics.

Foliage: Leaves have the following color: Spring/Summer upper surface:RHS 146A, Yellow-Green Group (Moderate Olive Green ARS). Centralmarkings: RHS 200A Brown Group (Dark, grayish reddish brown ARS).

Flowers: In bud: RHS 62C, Red-Purple Group (Light Purplish-Pink ARS). Inflower: RHS 155B White Group (ARS Yellowish White).

Fruit: RHS 151A Yellow Green Group (ARS Strong Greenish Yellow).

Habit: This cultivar is not stoloniferous.

Hardiness: Cold hardy to USDA Zone 3 (-40° -34° C.).

Disease: Plants grown in Canby, Oreg., show moderate susceptibility topowdery mildew. Plants are susceptibile to root rot when grown under wetconditions.

DESCRIPTION OF PARENT PLANTS

This Tiarella hybrid has characteristics that make it unique from itsparents--Tiarella `Pinwheel`, which has divided and cut foliage andslight foliar markings, and the other parent, a deeply lobed Tiarellaseedling with no markings. Unlike its parents, Tiarella `Mint Chocolate`has deeply lobed, highly colored foliage and tawny-pink flowers inprofusion. No other Tiarella in commerce known to me resembles Tiarella`Mint Chocolate`.

I claim:
 1. A new and distinct hybrid Tiarella plant substantially asshown and described, characterized by deeply lobed, highly coloredfoliage and tawny-pink flowers in profusion.